Loosely woven fabrics have many uses, for example, as substrates or reinforcing fabrics for a variety of end products including adhesive tapes, such as duct tape, athletic tapes, medical tapes, auto-harness wrap tape, and so forth; fabrics impregnated with wax and other finishes, such as tack cloths, bone wrap, ammunition wrap, and so forth; wall coverings used in home and industrial wall decorations; and laminated fabrics used in clothing, shoes, and furniture. Gauzes are one type of loosely woven, open-mesh fabric which are particularly useful as substrates for various adhesive tapes. Open-mesh knit fabrics can also be used as substrates for adhesive tapes. However, where cost is an issue, woven fabrics are preferred because they are less costly to make than knits.
The strength, cost and tearability in use are all properties that are taken into consideration when selecting a substrate or reinforcing fabric for an adhesive tape and the fibers used in constructing the substrate or reinforcing fabric for such tapes will affect all of these properties.
Although gauzes are conventionally prepared from a spun cotton or cotton/synthetic blended yarn, the use of multi-filament synthetic yarns in the manufacture of gauze fabric is highly desirable, because of the strength and cost savings advantages provided by such synthetic yarns over spun yarns. In the case of gauze substrates for adhesive tapes, the use of synthetic yarns would provide gauze having lower yarn count yet adequate strength and tearability. However, because of the natural slickness of synthetic yarns, it has been difficult to prevent fabric weave distortion, and in particular in the low count constructions of gauze fabrics.
In the case of gauze used as a duct tape substrate, fabric constructions and yarn counts with traditional spun yarns have reached the lower limits while providing adequate properties, leaving limited opportunities for further cost reductions. Conventional low end woven duct tape fabric has a construction of 18.times.8 and uses a spun cotton or polyester/cotton blended yarn in both warp and filling, the yarn counts generally being in the 30/1 to 40/1 range of cotton count. Spun yarn counts lower than 40/1 become too low in strength and/or too expensive for use in duct tape product lines. Fabric constructions such as 18.times.8 and lower, often perform poorly through the tape making process because of low fabric strength. Furthermore, the tape has poor appearance and poor tear characteristics.
Gauze fabrics including synthetic fibers are known in the art. For example, U.S. Pat. No. 4,303,724 disclosed duct tape incorporating a gauze substrate woven of texturized or false-twist yarns in the filling direction which are continuous filament yarns which have been given increased bulk and loft by the introduction of numerous loops, curls and coil. Texturized yarns perform more like conventional spun yarns. Gauze substrates also incorporating texturized yarns for use in making vinyl products are disclosed in U.S. Pat. Nos. 4,935,293 and 5,043,208. Adhesive tape substrates are disclosed in U.S. Pat. No. 4,654,254 wherein the substrate is a gauze fabric of cotton warp yarn and textured polyester filler yarns
U.S. Pat. No. 4,304,813 disclosed warp knit, weft inserted all synthetic continuous filament yarn fabric, preferably polyester, as a substrate for a pressure sensitive adhesive. Even though knit construction provides greater stability when using slick synthetic fibers, a woven construction is less expensive than knit and, thus, highly desirable.
U.S. Pat. No. 4,439,482 disclosed a base fabric for adhesive tapes in which a multi-filament yarn without twists, i.e., a flat yarn, of polyester fibers having a specific residue in molecular chain was used as the warp.
U.S. Pat. No. 5,047,285 disclosed a 100% polyester fabric for use as base fabric for tapes wherein a preferably continuous filament, warp yarn carries a non-hardening agglutinating sizing. Related U.S. Pat. No. 5,279,891 disclosed a woven tape support fabric comprising ribbonized warp yarn processed with agglutinating resin sizing to a specified add-on content.
U.S. Pat. Nos. 4,874,019 and 4,925,726 disclose wall covering substrates formed of texturized, continuous multi-filament yarns having hydrophilic characteristics.
Gauze fabrics comprising synthetic yarns which do not involve preparatory procedures such as texturizing and sizing to achieve lower costs and greater efficiency are being sought.